Polygalactomannans are polysaccharides that are found in the endosperm material of seeds from leguminous plants such as Cyamopsis tetragonoloba (guar gum), Cesalpinia spinosa (tara gum), Ceratonia siliqua (locust bean gum), and other members of the Leguminosae family. A polygalactomannan is composed of backbone of 1→4-linked β-D-mannopyranosyl units with recurring 1→6-linked α-D-galactosyl side groups branching from the number 6 carbon of a mannopyranose residue in the backbone. The galactomannan polymers of the different Leguminosae species defer from one another in the frequency of the occurrence of the galactosyl side units branching from the polymannopyranose backbone. The average ratio of D-mannosyl to D-galactosyl units in the polygalactomannan contained in guar gum is approximately 2:1, approximately 3:1 for tara gum, and approximately 4:1 for locust bean gum. Another important source of polygalactomannan is Cassia tora and Cassia obtusifolia (collectively known as Cassia gum). The average ratio of D-mannosyl to D-galactosyl units in the polygalactomannan contained in Cassia gum is at least 5:1.
Polygalactomannan obtained from Cassia gum is schematically represented in the structure below:
wherein n is an integer representing the number of repeating units in the polymer. The cationic polygalactomannan used in the practice of this invention typically has a weight average molecular weight (Mw) ranging from 200,000 to 3,000,000 Daltons in one aspect, 300,000 to 2,000,000 Daltons in another aspect, and 400,000 to 1,000,000 Daltons in a further aspect of the invention.
Polygalactomannans are hydrocolloids that have a high affinity for water. They have been widely used as suspending, thickening, emulsifying, and gelling agents in applications as diverse as foodstuffs, coatings, personal care compositions and in oil well fracturing fluids. Although the use of these polymers has been met with great success, polygalactomannans used in their natural form have suffered some drawbacks from a water solubility standpoint. An unsubstituted polymannose backbone is completely insoluble in water. The attachment of galactose side units to the C-6 atom in the recurring mannose residues of the polymannose backbone increases the water solubility of the polymer, particularly in cold water (i.e., ambient temperature and below). The greater the galactose side unit substitution, the greater is the cold water solubility properties of the polygalactomannan. Consequently, lower ratios of D-mannosyl to D-galactosyl units in the polygalactomannan leads to better cold water solubility. For example, guar gum polygalactomannan (average D-mannosyl to D-galactosyl ratio 2:1) is soluble in cold water; while Cassia gum polygalactomannan (average D-mannosyl to D-galactosyl ratio of 5:1) is only sparingly soluble in cold and hot water.
U.S. Pat. No. 4,753,659 to Bayerlein et al. discloses inter alia that improved cold water solubility can be imparted to Cassia gum by chemically modifying the polygalactomannan. Disclosed uses for the chemically modified Cassia gum polygalactomannans include textile printing applications, oil well drilling mud auxiliaries, and mining and explosive applications.
U.S. Pat. No. 5,733,854 to Chowdhary et al. discloses a chemically modified guar gum and a method for its preparation. According to Chowdhary et al., cationically functionalized guar gum polygalactomannans produce clear and colorless solutions upon dispersal in aqueous or organic solvents. A disclosed application for the cationically functionalized guar gum includes its incorporation into detergent compositions for human and household uses. Other disclosed uses include personal care and cosmetic applications. The use of cationically functionalized Cassia gum in hair fixative formulations is not discussed.
Accordingly, there exists is a need for a cationic polygalactomannan with a high degree of cationic functionalization which is suitable for use in thickener, stabilizer, emulsifier, spreading aid, hair fixative and in carrier applications for enhancing the efficacy, deposition and delivery of chemically, cosmetically and physiologically active ingredients.
The desire to have one's hair retain a particular set or coiffure is widely held. A common methodology for accomplishing this is by applying a “fixative” to the hair. Hair fixative compositions can assist in manipulating (styling) the hair, and provide temporary benefits in holding the shape of the hair style (fixing) and maintaining the shine or appearance (grooming, restyling) of the coiffure during the day or between hair washing periods with water or shampoo, or between subsequent hair setting procedures.
The term “fixative” as applied to the cationic Cassia polymers of the present invention encompasses the properties of film-formation, adhesion, or coating deposited on a keratinous surface (e.g., hair and skin) on which the polymer is applied. The terms “hair styling and hair fixative” as commonly understood in the hair care art, and as used herein, refer collectively to hair setting agents that are hair fixatives and film formers and which are topically applied to the hair to actively contribute to the ease of styling and/or holding of a hair set, and to maintain the restylability of the hair set. Hence, hair setting compositions include hair styling, hair fixative, and hair grooming products that conventionally are applied to the hair (wet or dry) in the form of gels, rinses, emulsions (oil-in-water, water-in-oil or multiphase), such as lotions and creams, pomades, sprays (pressurized or non-pressurized), spritzes, foams, such as mousses, shampoos, solids, such as sticks, semisolids and the like, or are applied from a hair setting aid having the hair setting composition impregnated therein or coated thereon, to leave the hair setting agent in contact on the hair for some period until removed, as by washing.
Various objective and subjective methods are used to measure the efficacy of a hair fixative composition. One method commonly employed evaluates the resistance of the hair set to high humidity conditions as a function of curl retention. When curl retention is measured under controlled ambient temperatures in the range of about 23° to about 27° C. and high humidity in the range of about 80 to 90% relative humidity (RH), it is commonly referred to as high humidity curl retention (HHCR). Most conventional hair fixative formulations are marginally effective, typically providing an HHCR of about 70% of the initial curl for a period of not more than about 0.75 hours. Thus there is an ongoing need for an increase in the HHCR of hair fixative or hair setting formulations.
One of the most common needs in the hair fixative market today is stiff hair feel and stiff hold. This is especially desirable in men's styling, in products targeting younger consumers, and in regions where hair is more tenacious and requires greater holding power such as Asia and Latin America. Thus, the demand for stiff hold is a growing trend. Traditional stiff-hold styling polymers have many deficiencies including poor humidity resistance, tackiness or stickiness and excessive flaking. Accordingly, there is an ongoing need for an easy-to-use polymer that provides both superior stiffness and superior high humidity style retention performance.
Also of importance are the aesthetic characteristics and appearance of hair fixative or hair setting compositions before, during, and after application to hair. In one aspect of the invention, the product viscosity should be non-runny to avoid dripping during application. In another aspect, product clarity is substantially transparent or clear in order to obtain a “clean” product appearance. The product should be easy to spread, have a smooth texture, a non-tacky feel, and be able to dry relatively quickly on the hair.